This article investigates the seed exomorphic characteristics of 14 taxa of Lepidium L. in Brassicaceae by light microscope and scanning electron microscope (SEM). The exomorphic characteristics of the seed are size, seed shape, seed colour, seed wings, and seed surface pattern. All characteristics of the seeds are described, illustrated, and compared in this article. The results of SEM at higher magnification showed 6 types of seed surface patterns: tuberculate, reticulate, ruminate, reticulate-tuberculate, reticulate-areolate, and reticulate-fovate. In these seed surface patterns, there were diagnostic characteristics and differences at the specific level for Lepidium.